Test Technology Of Material Electromagnetic Properties Based On Rectangular Waveguide Transmission Lines

The measuring method of the material electromagnetic parameters based on rectangularwaveguide transmission lines were mainly studied in this paper. The electromagnetic characteristicsand electromagnetic mechanism of materials were analyzed in briefly, and the common method ofthe material electromagnetic parameters measurement and the development situation of transmissionline material test were introduced.The basic principle of the material electromagnetic properties measurement based onrectangular waveguide transmission line were mainly analyzed. The multiple reflection effect wasin-depth studied. The vector equations calculated characteristic impedance and propagation constantwere deduced from the material of the scattering parameter which, for the waveguide transmissionline, derived the formula to calculate the permittivity and permeability from the characteristicimpedance and propagation constant.The scattering parameters of actual measurement were substituted by the scattering parametersthat were simulated and calculated using high frequency structure simulation software HFSS, thenthe electromagnetic parameters of PTFE material were calculated by MATLAB programmingsoftware.The selection range of material thickness and the resonance problem were presented bythree dimensional graphics mode and the results of previous researches were confirmed. Themeasurement error of the material permeability and permittivity are in relation to the materialthickness and working frequency, which was discussed, and the selection range of material thicknesswas given. The electromagnetic properties of materials testing had reference value for transmissionlines. The test of scattering parameters of several common materials in test fixture was completed byvector network analyzer in X band and K band, the electromagnetic properties of the material ofdifferent thickness was measured which were agreed well with the theoretical value.The testing frequency of electromagnetic characteristics of rectangular waveguide material was extended to the terahertz frequency. The test fixture of2mm band standard rectangular waveguidewas designed for THz materials measurement, the fixture embedding algorithm was studied deeply,and the embedding of test fixture was completed. The measurement of the electromagneticparameters of the2mm band standard rectangular waveguide transmission lines were accomplished.At last, the results of the electromagnetic parameters of materials were given at the end of paper.